U.S. NEWS & WORLD REPORT
December 21, 2018
By Heidi Godman
Saving for a rainy day is an important way to cope with financial problems. You can tap into the extra cash when you lose a job or suddenly have to shell out money to fix your car. So wouldn’t it be great if you could apply a rainy-day savings plan to your brain and have a healthy reserve that kicks in when neurons go south due to old age or dementia?
Scientists believe it may be possible. The concept is called cognitive reserve. “It’s an active coping process that’s built up over a lifetime. What you do in life can contribute to it, even in older age,” says Yaakov Stern, a cognitive neuroscientist at Columbia Medical School who has studied cognitive reserve for decades.
Secret Brain Stash
Cognitive reserve describes neural networks that are resilient and can maintain function even when there’s damage to brain cells.
Researchers began studying this phenomenon in the 1980s, when they noticed in autopsy studies that some older adults had plaques and tangles in the brain (the hallmarks of Alzheimer’s disease), even though they hadn’t shown any signs of the condition when they were alive.
This finding has been confirmed in subsequent research, including the famous study of almost 700 Catholic nuns in the U.S. Many of the nuns, like Sister Mary – a feisty woman who was able to remember short lists, grasp explanations and recall recent events right up until she died at age 101 – had high cognitive test scores before death, despite having abundant signs of Alzheimer's disease in their brains. “There’s a significant percentage of people who have plaques and tangles but never (appear to) suffer the disease in their lifetime,” Stern explains.
Today it is widely accepted that cognitive reserve may be the secret sauce enabling some people to continue functioning when age-related brain changes, such as shrinkage or disease, set in. “Some people can cope with damage or change to the brain more than others. They have more efficient or resilient cognitive networks that can cope with the damage,” Stern says.
This cognitive reserve or resilience is thought to either delay dementia or reduce its effects, although it’s not clear how long that lasts, and it doesn’t mean these people won’t eventually get dementia.
Possible Contributors to Cognitive Reserve
Why do some people seem to have high levels of cognitive reserve when others don’t? Many studies have associated high cognitive reserve with high education levels and intellectually challenging jobs, such as being an attorney or an accountant, as opposed to manual labor. The idea is that challenging the brain may help stimulate and promote connections between neurons.
But there are other possibilities for what creates a higher cognitive reserve, like the genetic luck of the draw. People seem to have higher cognitive reserve when they have higher than average:
- Brain size
- Memory capacity
In September, an international group of scientists that included Stern came up with an official list of influences that may contribute to cognitive reserve over a lifetime. In addition to intelligence, education and occupation, they listed:
- Physical exercise. Getting quality and consistent exercise is associated with better brain health.
- Leisure activities and social engagement.“It doesn’t matter what kind of activities, it just needs to be more activities. The more the better. It can be brain-stimulating activity or just getting together with friends,” Stern says.
Boosting Your Cognitive Reserve
Some of the suspected contributors to cognitive reserve are now part of the recipe used by academic brain performance clinics to build more of it. One of the main ingredients is exercise. “Exercise stimulates the production of brain-derived neurotrophic factor, which helps new connections grow. If you have more connections in the brain circuits, then if some are lost or damaged by disease, you have additional connections that can still do the work for the brain without losing function,” says Ian Robertson, a research professor at the Center for BrainHealth at the University of Texas—Dallas.
Robertson says exercise also helps improve the insulation of the brain’s wiring that can become faulty with age or disease.
While we don’t know yet exactly how much exercise is required to help build cognitive reserve, Robertson suggests going with the Physical Activity Guidelines for Americans, which recommend that adults get at least 150 minutes per week of moderate-intensity exercise, like brisk walking or water aerobics.
Another promising but not yet proven approach may be cognitive training, which uses computer programs and other strategies to improve memory, attention and processing speed. Robertson is a fan, but the method is not supported by all experts. “The question," Stern says, "is does it transfer to your everyday life? There are some labs working with more complex games, and it looks like they are showing the transfer of training.” He recommends seeking out an academic center if you’re considering it.
Other approaches to try to build cognitive reserve include:
- Stress reduction. Robertson says chronic exposure to stress hormones can cut brain connections and cause the memory part of the brain (the hippocampus) to shrink. Reducing stress helps your memory improve. Tried and true stress relievers include exercise, meditation and yoga.
- A healthy diet. Strong evidence suggests a Mediterranean-style diet promotes brain health. The diet is rich in fruits, vegetables, legumes, seeds, nuts, olive oil and whole grains, plus moderate amounts of fish, poultry and wine and low amounts of red meat and meat products.
- Proper sleep. Aim for seven or eight hours per night. “During sleep our brain clears out amyloid (plaque) that’s accumulated throughout the day. More amyloid contributes to the disease process,” Robertson says. “Long-term sleep problems can diminish cognitive reserve.”
- Social interaction.“Complex mental activity builds cognitive reserve through the use-it-or-lose-it principal. The best form of complex activity is interacting with other complex human beings,” Robertson notes. “And when you spend time with others, you get the release of oxytocin, a bonding hormone that is a wonderful antidote to stress.”
- Having a sense of purpose. Find something that motivates you to get out of bed in the morning, such as a hobby or volunteering. “We don’t know why yet, but it may be that a sense of purpose makes you inclined to stay active, and if we do something for someone else we get a release of oxytocin and dopamine, which is like a natural antidepressant,” Robertson says.
- Learning new things. “Learning something new, like how to play a new instrument or speak a second language, is incredibly powerful for the brain and helps form new brain connections,” Robertson notes.
- Maintaining a positive attitude. “If you have negative expectations about aging, your cognitive function declines slightly and it may indirectly diminish cognitive reserve,” Robertson says.
The Big Payoff for Your Health
We don’t know for sure if attempting to build cognitive reserve actually works. Most studies on the subject are observational, so the findings cannot prove cause and effect.
But since the recommended actions are also good for overall health, you have nothing to lose by trying to bank your cognitive spending power. And you may wind up with an old age ledger that has a few extra years of better thinking skills and improved quality of life. [read more]